The present invention relates to forklift trucks, and in particular, relates to an improved method and apparatus for preventing condensation from accumulating on electrical components and connectors in the control handle of a forklift truck.
There are a number of applications in which fork lifts are used in environments that may precipitate the formation of undesirable moisture. One example is in the storage and retrieval of frozen food items. In these applications, forklift trucks typically move between cold storage, where temperatures can be as low as −25 degrees F., and a warm warehouse environment, in which the temperature can exceed 100 degrees F. Under these operating conditions, the operator controls and operator control handles are subjected to a significant degree of thermal stress, which can result in premature failure. For example, because the temperature of the cold storage application is commonly less than the dew point of the warmer environment, condensation can accumulate on the electrical components in the operator control handle. Subsequently, when the truck travels back into the cold environment, the condensation will freeze on the components, thereby subjecting the components and associated connecting wires to thermal and mechanical stress which can cause corrosion, electrical damage, breakage and failure.
To prevent these problems, heating elements are often provided in operator control handles. These elements are typically discrete resistors wired into the control circuit. Alternatively, heaters provided on flexible heating elements can be provided. These devices, however, typically heat a general area and are therefore not particularly effective in modifying the environment around a specific component. Furthermore, these components and circuits typically have no function other than heating, and therefore may add significant size and complexity to the operator handle without a proportional increase in functionality.
What is therefore needed is a method and apparatus for supplying heat specifically to the components of a control/circuit or system to limit the accumulation of condensation thereon, and further a method and apparatus for supplying heat to the components of a lift truck electrical system which does not add bulk and complexity to the system, and is also easy to manufacture and assemble.